Dissolvable solid article containing anti-bacterial actives

ABSTRACT

Disclosed is a dissolvable solid article, comprising by weight of the article: from about 10% to about 50% of a water soluble polymer; from about 20% to about 80% of a surfactant; from about 0.5% to about 2% of diaminocarboxylic acid chelants and salts thereof having an average molecular weight in acid form of from about 250 to about 450 daltons and having a weighted log P value at pH 4 of from about −12 to about −7; from about 0.1% to about 6% of an aromatic carboxylic acid and salts thereof having an average molecular weight in acid form of from about 100 to about 400 daltons and having a weighted log P value at pH 4 of from about −2 to about 4; from about 0.1% to about 18% of an non-aromatic organic alpha hydroxy acid and salts thereof; wherein the dissolvable solid article has a pH of from about 3 to about 5.1 when dissolved with 30 parts water to 1 part of the dissolvable solid article. The present invention provides dissolvable solid articles which provide anti-bacterial benefit even after dissolution of the articles, while controlling the concentration of anti-bacterial active ingredients in the solid articles.

FIELD OF THE INVENTION

The present invention relates to a dissolvable solid article, comprisingby weight of the article: from about 10% to about 50% of a water solublepolymer; from about 20% to about 80% of a surfactant; from about 0.5% toabout 2% of diaminocarboxylic acid chelants and salts thereof having anaverage molecular weight in acid form of from about 250 to about 450daltons and having a weighted log P value at pH 4 of from about −12 toabout −7; from about 0.1% to about 6% of an aromatic carboxylic acid andsalts thereof having an average molecular weight in acid form of fromabout 100 to about 400 daltons and having a weighted log P value at pH 4of from about −2 to about 4; from about 0.1% to about 18% of annon-aromatic organic alpha hydroxy acid and salts thereof; wherein thedissolvable solid article has a pH of from about 3 to about 5.1 whendissolved with 30 parts water to 1 part of the dissolvable solidarticle. The present invention provides dissolvable solid articles whichprovide anti-bacterial benefit even after dissolution of the articles,while controlling the concentration of anti-bacterial active ingredientsin the solid articles.

BACKGROUND OF THE INVENTION

Flexible and dissolvable solid articles comprising surfactant(s) and/orother active ingredients in a water-soluble polymeric carrier or matrixare well known. Such articles are particularly useful for deliveringsurfactants and/or other active ingredients upon dissolution in water.In comparison with traditional granular or liquid forms in the sameproduct category, such articles have better structural integrity, aremore concentrated and easier to store, ship/transport, carry, andhandle. In comparison with the solid tablet form in the same productcategory, such articles can provide faster dissolution and/or moreaesthetic appeal to the consumers.

Such dissolvable solid articles are generally used by dissolving thearticles with, for example, 10-30 parts of water to 1 part of thearticle water. The concentration of ingredients contained in thearticles are diluted during and after dissolution. There exists a needfor dissolvable solid articles to provide anti-bacterial benefit to theapplied substrate, for example, skin and/or hair when the articles arepersonal care products. However, when containing an anti-bacterialactive ingredient at a level enough to provide anti-bacterial benefitafter dissolution of the solid article, the concentration of such activeingredient becomes too high in the solid articles before dissolution.Some country's regulations require an upper limitation of theconcentration of such anti-bacterial active ingredient in the articlebefore dissolution.

Therefore, there is a need for dissolvable solid articles which provideanti-bacterial benefit even after dissolution of the article, whilecontrolling the concentration of anti-bacterial active ingredient in thesolid articles.

SUMMARY OF THE INVENTION

The present invention is directed to a dissolvable solid article,comprising by weight of the article:

-   -   a. from about 10% to about 50% of a water soluble polymer;    -   b. from about 20% to about 80% of a surfactant;    -   c. from about 0.5% to about 2% of diaminocarboxylic acid        chelants and salts thereof having an average molecular weight in        acid form of from about 250 to about 450 daltons and having a        weighted log P value at pH 4 of from about −12 to about −7;    -   d. from about 0.1% to about 6% of an aromatic carboxylic acid        and salts thereof having an average molecular weight in acid        form of from about 100 to about 400 daltons and having a        weighted log P value at pH 4 of from about −2 to about 4;    -   e. from about 0.1% to about 18% of a non-aromatic organic alpha        hydroxy acid and salts thereof;

wherein the dissolvable solid article has a pH of from about 3 to about5.1 when dissolved with 30 parts water to 1 part of the dissolvablesolid article.

In one embodiment, the dissolvable solid article of the above featurehas a pH of from about 3.5 to about 4.9 when dissolved with 30 partswater to 1 part of the dissolvable solid article.

In one embodiment, the dissolvable solid article of any of the abovefeatures has a pH of from about 3.8 to about 4.8 when dissolved with 30parts water to 1 part of the dissolvable solid article.

In one embodiment, the dissolvable solid article of any of the abovefeatures further comprises from about 0.1% to about 2.0% of a diolhaving an average molecular weight of from about 90 to about 500 daltonsand a weighted log P value at pH 4 of from about −1 to about 12.

In one embodiment, the dissolvable solid article of any of the abovefeatures comprises two or more flexible, dissolvable, porous sheets.

In one embodiment, the dissolvable solid article of any of the abovefeatures has a density ranging from about 0.050 g/cm³ to about 0.380g/cm³.

The present invention provides dissolvable solid articles which provideanti-bacterial benefit even after dissolution of the articles, whilecontrolling the concentration of anti-bacterial active ingredients inthe solid articles. By the combination of specific anti-bacterial activeingredients and the use of such combination at a specific pH, it becomespossible to provide anti-bacterial benefit even after dissolution of thearticles, while controlling the concentration of each anti-bacterialactive ingredient in the solid articles.

These and other aspects of the present invention will become moreapparent upon reading the following detailed description of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

While the specification concludes with claims particularly pointing outand distinctly claiming the invention, it is believed that the presentinvention will be better understood from the following description.

Herein, “comprising” means that other steps and other ingredients whichdo not affect the end result can be added. This term encompasses theterms “consisting of” and “consisting essentially of”.

All percentages, parts and ratios are based upon the total weight of thecompositions of the present invention, unless otherwise specified. Allsuch weights as they pertain to listed ingredients are based on theactive level and, therefore, do not include carriers or by-products thatmay be included in commercially available materials.

Herein, “mixtures” is meant to include a simple combination of materialsand any compounds that may result from their combination.

The term “molecular weight” or “M.Wt.” as used herein refers to theweight average molecular weight unless otherwise stated. The weightaverage molecular weight may be measured by gel permeationchromatography.

“QS” means sufficient quantity for 100%.

Diaminocarboxylic Acid Chelant

The dissolvable solid article of the present invention comprisesdiaminocarboxylic acid chelants and salts thereof. The diaminocarboxylicacid chelants and salts thereof are included in the article at a levelof from about 0.5% to about 2%, alternatively from about 0.75% to about1.5%, by weight of the article.

The diaminocarboxylic acid chelants and salts thereof useful herein arethose having an average molecular weight (in acid form) of from about250 to about 450 daltons, alternatively from about 250 to 350 daltons,and having a weighted log P value at pH 4 of from about −12 to about −7,from about −10 to about −8.

Such diaminocarboxylic acid chelants include, for example, those in thebelow table and salts thereof.

LogP at pH 4 MW Ethylenediaminetetraacetic acid −9.312 292.242-[3-[bis(carboxymethyl)amino]propyl- −9.864 306.27(carboxymethyl)amino]acetic acid1,2-Diaminopropane-N,N,N′,N′-tetraacetic acid −8.945 306.271,3-DIAMINO-2-PROPANOL-N,N,N′,N′- −10.843 322.27 TETRAACETIC ACIDN-(2-Hydroxyethyl)Ethylenediaminetriacetic Acid −7.486 278.262-[2-[2-[bis(carboxymethyl)amino]ethoxy]ethyl- −10.601 336.3(carboxymethyl)amino]acetic acid2-[[2-[bis(carboxymethyl)amino]cyclopropyl]- −10.634 304.25(carboxymethyl)amino]acetic acid pentetic acid −11.767 393.352-[3-[bis(carboxymethyl)amino]butan-2-yl- −8.462 320.3(carboxymethyl)amino]acetic acid ethylene glycolbis(2-aminoethyl)tetraacetic acid −10.732 380.35Among them, preferred are those in the below table and salts thereof.

LogP at pH 4 MW Ethylenediaminetetraacetic acid −9.312 292.242-[3-[bis(carboxymethyl)amino]propyl- −9.864 306.27(carboxymethyl)amino]acetic acid1,2-Diaminopropane-N,N,N′,N′-tetraacetic acid −8.945 306.271,3-DIAMINO-2-PROPANOL-N,N,N′,N′- −10.843 322.27 TETRAACETIC ACID2-[2-[2-[bis(carboxymethyl)amino]ethoxy]ethyl- −10.601 336.3(carboxymethyl)amino]acetic acidAmong them, more preferred is that in the below table and salts thereof.

LogP at pH 4 MW Ethylenediaminetetraacetic acid −9.312 292.24

Aromatic Carboxylic Acid

The dissolvable solid article of the present invention comprisesaromatic carboxylic acids and salts thereof. The aromatic carboxylicacids and salts thereof are included in the article at a level of fromabout 0.1% to about 6%, alternatively from about 0.2% to about 5%,alternatively from about 0.3% to about 4% by weight of the article.

The aromatic carboxylic acid and salts thereof useful herein are thosehaving an average molecular weight (in acid form) of from about 100 toabout 400 daltons, alternatively from about 105 to about 200 daltons,alternatively from about 110 to about 150 daltons, and having a weightedlog P value at pH 4 of from about −2 to about 4, from about −0.5 toabout 2, alternatively from about 0 to about 1.5.

Such aromatic carboxylic acids include, for example, those in the belowtable and salts thereof.

LogP at pH 4 MW Salicylic acid 0.289 138.1207 Benzoic acid 0.91 122.1213Hydroxycinnamic Acid 1.593 164.16 Capryloyl Salicylic Acid 3.27 264.32Orotic Acid −0.408 156.0963 Rosmarinic Acid 2.535 360.3148Pyridinedicarboxylic Acid −0.935 167.1189 Hydroxyphenyl PropamidobenzoicAcid 1.171 285.2946 Ferulic Acid 1.571 194.184 Chlorogenic Acid −1.46354.3087 Gallic Acid 0.573 170.1195 P−Anisic Acid 1.321 152.1473Cinnamic Acid 1.709 148.1586 Usnic Acid 1.228 344.3154 Caffeic Acid1.353 180.1574 Phthalic Acid 0.125 166.1308 2,6-Cresotic acid 1.006152.1473 2,3-DIHYDROXYBENZOIC ACID 0.07 154.1201 2,6-DIHYDROXYBENZOICACID −0.478 154.1201 2,4-DIHYDROXYBENZOIC ACID 0.208 154.12014-HYDROXYBENZOIC ACID 1.125 138.1207 2,5-Cresotic acid 1.154 152.1473 3Hydroxyanthranilic acid −0.729 153.1354 Gentisic acid 0.07 154.12012,4-Cresotic acid 0.902 152.1473 5-AMINO SALICYLIC ACID −1.191 153.1354Anthranilic acid −0.71 137.136Among them, preferred are those in the below table and salts thereof.

LogP at pH 4 MW Salicylic acid (sodium/potassium salicylate) 0.289138.1207 Benzoic acid (sodium benzoate) 0.91 122.1213 HydroxycinnamicAcid 1.593 164.16 Capryloyl Salicylic Acid 3.27 264.32 Rosmarinic Acid2.535 360.3148 Pyridinedicarboxylic Acid −0.935 167.1189 Ferulic Acid1.571 194.184 Gallic Acid 0.573 170.1195 P-Anisic Acid 1.321 152.1473Cinnamic Acid 1.709 148.1586 Usnic Acid 1.228 344.3154 Caffeic Acid1.353 180.1574 Gentisic acid 0.07 154.1201Among them, more preferred are those in the below table and saltsthereof.

LogP at pH 4 MW Salicylic acid (sodium/potassium salicylate) 0.289138.1207 Benzoic acid (sodium benzoate) 0.91 122.1213

As shown above, aromatic carboxylic acids and salts thereof arealternatively selected from the group consisting of: at least oneselected from salicylic acid and salts thereof; at least one selectedfrom benzoic acid and salts thereof; and mixtures thereof, alternativelyselected from the mixtures thereof. Salicylic acids and salts thereofcan be included in the article at a level of from about 0.1% to about2.5%, alternatively from about 0.2% to about 2%, alternatively fromabout 0.3% to about 1.5% by weight of the article. Benzoic acids andsalts thereof can be included in the article at a level of from about0.1% to about 5%, alternatively from about 0.2% to about 3%,alternatively from about 0.3% to about 2.5% by weight of the article.

Non-Aromatic Organic Alpha Hydroxy Acid

The dissolvable solid article of the present invention comprises anon-aromatic organic alpha hydroxy acid (organic AHA) and salts thereof.The non-aromatic organic AHAs and salts thereof are included in thearticle at a level of from about 0.1% to about 18%, alternatively fromabout 0.5% to about 12%, alternatively from about 1% to about 6%, stillalternatively from 1% to about 4%, and alternatively from about 1% toabout 3% by weight of the article.

The organic AHAs useful herein, and include, for example, those in thebelow table and salts thereof.

Citric acid Lactic acid Malic acid Tartaric acid Gluconic acid Glycericacid Xylonic acid Galactaric AcidAmong them, preferred are those in the below table and salts thereof.

Citric acid Lactic acid Gluconic acidAmong them, more preferred is that in the below table and salts thereof.

Citric acid

Non-Aha, Non-Aromatic Acid

The dissolvable solid article of the present invention may furthercomprise a non-AHA, non-aromatic acids and salts thereof. The non-AHA,non-aromatic acids and salts thereof can be included in the article at alevel of from about 0.1% to about 10%, alternatively from about 0.1% toabout 5%, alternatively from about 0.1% to about 3%, by weight of thearticle.

The non-AHA, non-aromatic acids useful herein include, for example,those in the below table and salts thereof.

Sorbic acid Succinic acid Phytic acid Acetic acid Malonic acid FumaricAcid Glyoxylic Acid HCl

Among them, preferred are organic acids and salts thereof, and morepreferred are those in the below table and salts thereof.

Sorbic acid Succinic acid Phytic acid Acetic acid

Diol

The dissolvable solid article of the present invention may furthercomprise a diol. The diol can be included in the article at a level offrom about 0.1% to about 2%, alternatively from about 0.25% to about1.5%, by weight of the article.

The diols useful herein are those having an average molecular weight offrom about 90 to about 500 daltons, alternatively from about 100 toabout 250 daltons, alternatively from about 110 to about 160 daltons,and having a weighted log P value at pH 4 of from about −1 to about 12,from about 0 to about 7, alternatively from about 0.5 to about 4.

Such diols useful herein include, for example, those in the below table.

LogP at pH 4 MW 1,2-Hexanediol 0.92 118.17 1,2-Octanediol 1.83 146.231,2-octacosanediol 10.952 426.76 1,2-octadecanediol 6.39 286.49311,2-hexadecanediol 5.478 258.44 1,2-tetradecanediol 4.565 230.38681,2-Decanediol 2.741 174.2805 1,2-Dodecanediol 3.653 202.33361,2-hexacosanediol 10.04 398.71 ARACHIDYL GLYCOL 7.302 314.551,2-Pentanediol 0.459 104.1476 1,3-Heptanediol 0.978 132.20071,5-Hexanediol 0.578 118.1742 1,3-Hexanediol 0.522 118.17421,2,6-Hexanetriol −0.31 134.1736 1-hexanol, 2-amino-5-methyl- −0.127131.216 7-Octene-1,2-Diol 1.437 144.21144 1-Methyl-1-octanol 3.172144.2545 Octan-2-ol 2.716 130.22792 Nonanol-3 3.24 144.2545

Among them, preferred are those in the below table.

LogP at pH 4 MW 1,2-Hexanediol 0.92 118.17 1,2-Octanediol 1.83 146.231,2-octacosanediol 10.952 426.76 1,2-octadecanediol 6.39 286.49311,2-hexadecanediol 5.478 258.44 1,2-Decanediol 2.741 174.28051,2-hexacosanediol 10.04 398.71 1,2-Pentanediol 0.459 104.14761,2,6-Hexanetriol −0.31 134.1736 7-Octene-1,2-Diol 1.437 144.21144

Among them, more preferred are those in the below table.

LogP at pH 4 MW 1,2-Hexanediol 0.92 118.17 1,2-Octanediol 1.83 146.23

Water-Soluble Polymer (“Polymer Structurant”)

The present invention comprises water-soluble polymer that functions asa structurant. The water soluble polymer is included in the article at alevel of from about 10% to about 50%, alternatively from about 15% toabout 40%, alternatively from about 18% to about 30%, by weight of thearticle. As used herein, the term “water-soluble polymer” is broadenough to include both water-soluble and water-dispersible polymers, andis defined as a polymer with a solubility in water, measured at 25° C.,of at least about 0.1 gram/liter (g/L). In some embodiments, thepolymers have a solubility in water, measured at 25° C., of from about0.1 gram/liter (g/L). to about 500 grams/liter (g/L). (This indicatesproduction of a macroscopically isotropic or transparent, colored orcolorless solution). The polymers for making these solids may be ofsynthetic or natural origin and may be modified by means of chemicalreactions. They may or may not be film-forming. These polymers should bephysiologically acceptable, i.e., they should be compatible with theskin, mucous membranes, the hair and the scalp.

The terms “water-soluble polymer” and “polymer structurant” are usedinterchangeably herein. Furthermore, whenever the singular term“polymer” is stated, it should be understood that the term is broadenough to include one polymer or a mixture of more than one polymer. Forinstance, if a mixture of polymers is used, the polymer solubility asreferred to herein would refer to the solubility of the mixture ofpolymers, rather than to the solubility of each polymer individually.

The one or more water-soluble polymers of the present invention areselected such that their weighted average molecular weight is from about40,000 to about 500,000, in one embodiment from about 50,000 to about400,000, in yet another embodiment from about 60,000 to about 300,000,and in still another embodiment from about 70,000 to about 200,000. Theweighted average molecular weight is computed by summing the averagemolecular weights of each polymer raw material multiplied by theirrespective relative weight percentages by weight of the total weight ofpolymers present within the porous solid.

A variety of water-soluble polymers can be used in the presentinvention, as shown below. Among them, highly preferred is polyvinylalcohols.

The water-soluble polymer(s) of the present invention can include, butare not limited to, synthetic polymers including polyvinyl alcohols,polyvinylpyrrolidones, polyalkylene oxides, polyacrylates, caprolactams,polymethacrylates, polymethylmethacrylates, polyacrylamides,polymethylacrylamides, polydimethylacrylamides, copolymers of acrylicacid and methyl methacrylate, polyethylene glycol monomethacrylates,polyurethanes, polycarboxylic acids, polyvinyl acetates, polyesters,polyamides, polyamines, polyethyleneimines, maleic/(acrylate ormethacrylate) copolymers, copolymers of methylvinyl ether and of maleicanhydride, copolymers of vinyl acetate and crotonic acid, copolymers ofvinylpyrrolidone and of vinyl acetate, copolymers of vinylpyrrolidoneand of caprolactam, vinyl pyrollidone/vinyl acetate copolymers,copolymers of anionic, cationic and amphoteric monomers, andcombinations thereof.

The water-soluble polymer(s) of the present invention may also beselected from naturally sourced polymers including those of plant originexamples of which include karaya gum, tragacanth gum, gum Arabic,acemannan, konjac mannan, acacia gum, gum ghatti, whey protein isolate,and soy protein isolate; seed extracts including guar gum, locust beangum, quince seed, and psyllium seed; seaweed extracts such asCarrageenan, alginates, and agar; fruit extracts (pectins); those ofmicrobial origin including xanthan gum, gellan gum, pullulan, hyaluronicacid, chondroitin sulfate, and dextran; and those of animal originincluding casein, gelatin, keratin, keratin hydrolysates, sulfonickeratins, albumin, collagen, glutelin, glucagons, gluten, zein, andshellac.

Modified natural polymers are also useful as water-soluble polymer(s) inthe present invention. Suitable modified natural polymers include, butare not limited to, cellulose derivatives such ashydroxypropylmethylcellulose, hydroxymethylcellulose,hydroxyethylcellulose, methylcellulose, hydroxypropylcellulose,ethylcellulose, carboxymethylcellulose, cellulose acetate phthalate,nitrocellulose and other cellulose ethers/esters; and guar derivativessuch as hydroxypropyl guar.

Suitable water-soluble polymers of the present invention includepolyvinyl alcohols, polyvinylpyrrolidones, polyalkylene oxides, starchand starch derivatives, pullulan, gelatin,hydroxypropylmethylcelluloses, methycelluloses, andcarboxymethycelluloses.

More preferred water-soluble polymers of the present invention includepolyvinyl alcohols, and hydroxypropylmethylcelluloses. Suitablepolyvinyl alcohols include those available from Celanese Corporation(Dallas, Tex.) under the Celvol trade name including, but not limitedto, Celvol 523, Celvol 530, Celvol 540, Celvol 518, Celvol, 513, Celvol508, Celvol 504, and combinations thereof. Suitablehydroxypropylmethylcelluloses include those available from the DowChemical Company (Midland, Mich.) under the Methocel trade nameincluding, but not limited, to Methocel E50, Methocel E15, Methocel E6,Methocel E5, Methocel E3, Methocel F50, Methocel K100, Methocel K3,Methocel A400, and combinations thereof including combinations withabove mentioned hydroxypropylmethylcelluloses.

Most preferred water-soluble polymers of the present invention arepolyvinyl alcohols characterized by a degree of hydrolysis ranging fromabout 40% to about 100%, alternatively from about 50% to about 95%,alternatively from about 70% to about 92%, alternatively from about 80%to about 90%. Commercially available polyvinyl alcohols include thosefrom Celanese Corporation (Texas, USA) under the CELVOL trade nameincluding, but not limited to, CELVOL 523, CELVOL 530, CELVOL 540,CELVOL 518, CELVOL 513, CELVOL 508, CELVOL 504; those from KurarayEurope GmbH (Frankfurt, Germany) under the Mowiol® and POVAL™ tradenames; and PVA 1788 (also referred to as PVA BP17) commerciallyavailable from various suppliers including Lubon Vinylon Co. (Nanjing,China), for example, BP-17 having 86-90% degree of hydrolysis,Approximate MW (weight average)=70,000-120,000 daltons, available fromLiwei Chemical Co. Ltd., China; and combinations thereof. In aparticularly preferred embodiment of the present invention, theflexible, porous, dissolvable solid sheet article comprises from about10% to about 25%, alternatively from about 15% to about 23%, by totalweight of such article, of a polyvinyl alcohol having a weight averagemolecular weight ranging from 80,000 to about 150,000 Daltons and adegree of hydrolysis ranging from about 80% to about 90%.

Surfactant

The dissolvable solid article of the present invention comprises asurfactant. The surfactant is included in the article at a level of fromabout 20% to about 80%, alternatively from about 23% to about 75%,alternatively from about 35% to about 65%, by weight of the article. Thesurfactant comprises a blend of Group I and Group II surfactants. Theblend of surfactants of the present invention comprises one or moresurfactants from Group I and one or more surfactants from Group II.Group I surfactants include anionic surfactants, and Group IIsurfactants include amphoteric surfactants, zwitterionic surfactants,and combinations thereof. In one embodiment of the present invention,the ratio of Group I to Group II surfactants is from about 90:10 toabout 55:45. In yet another embodiment of the present invention theratio of Group I to Group II surfactants is from about 85:15 to about65:35.

Group I Surfactants

The Group I surfactants of the present invention include one or moreanionic surfactants. Suitable anionic surfactant components for use inthe Dissolvable Article herein include those which are known for use inhair care or other personal care cleansing compositions. Theconcentration of the anionic surfactant component in the compositionshould be sufficient to provide the desired cleaning and latherperformance, from about 6.5% to about 71% weight % of dry solids of aGroup I surfactant.

Anionic surfactants suitable for use in the compositions includesulfate-free surfactants. Such sulfate-free surfactants can comprise amaterial derived from an amino acid such as mono and dicarboxylate saltssuch as glutamate, glycinate, taurate, alaninate or sarcosinate.Examples include sodium lauroyl glutamate, sodium cocoyl glutamate,potassium lauroyl glutamate, sodium cocoyl alaninate, sodium cocoylglycinate, sodium lauroyl sarcosinate, sodium cocoyl sarcosinate, sodiumcocoyl methyl taurate, sodium lauryl methyl isethionate, sodium cocoylisethionate, or sodium oleoyl sarcosinate.

Anionic surfactants suitable for use in the compositions include alkyland alkyl ether sulfates. These materials have the respective formulaeROSO3M and RO(C2H4O)xSO3M, wherein R is alkyl or alkenyl of from about 8to about 18 carbon atoms, x is an integer having a value of from 1 to10, and M is a cation such as ammonium, alkanolamines, such astriethanolamine, monovalent metals, such as sodium and potassium, andpolyvalent metal cations, such as magnesium, and calcium. Alternatively,R has from about 8 to about 18 carbon atoms, alternatively from about 10to about 16 carbon atoms, even alternatively from about 11 to about 14carbon atoms, in both the alkyl and alkyl ether sulfates. The alkylether sulfates are typically made as condensation products of ethyleneoxide and monohydric alcohols having from about 8 to about 24 carbonatoms. The alcohols can be synthetic or they can be derived from fats,e.g., coconut oil, palm kernel oil, tallow. Synthetic alcohols mayinclude the grades available via Shell Chemical Co. under the NEODOLtrade name as NEODOL 91 (C9-11 alcohols), NEODOL 23 (C12-13 alcohols),NEODOL 25 (C12-15 alcohols), NEODOL 45 (C14-15 alcohols), and NEODOL 135(C11-C13-C15 alcohols). Lauryl alcohol and straight chain alcoholsderived from coconut oil or palm kernel oil are preferred. Such alcoholsare reacted with between about 0 and about 10, in one embodiment fromabout 2 to about 5, in another embodiment about 3, molar proportions ofethylene oxide, and the resulting mixture of molecular species having,for example, an average of 3 moles of ethylene oxide per mole ofalcohol, is sulfated and neutralized.

Other suitable anionic surfactants are the water-soluble salts oforganic, sulfuric acid reaction products conforming to the formula[R1-503-M] where R1 is a straight or branched chain, saturated,aliphatic hydrocarbon radical having from about 8 to about 24,alternatively about 10 to about 18, carbon atoms; and M is a cationdescribed hereinbefore.

Still other suitable anionic surfactants are the reaction products offatty acids esterified with isethionic acid and neutralized with sodiumhydroxide where, for example, the fatty acids are derived from coconutoil or palm kernel oil; sodium or potassium salts of fatty acid amidesof methyl tauride in which the fatty acids, for example, are derivedfrom coconut oil or palm kernel oil. Other similar anionic surfactantsare described in U.S. Pat. Nos. 2,486,921; 2,486,922; and 2,396,278.

Other anionic surfactants suitable for use in the compositions are thesuccinnates, examples of which include disodiumN-octadecylsulfosuccinnate; disodium laurylsulfosuccinate; diammoniumlaurylsulfosuccinate; tetrasodiumN-(1,2-dicarboxyethyl)-N-octadecylsulfosuccinnate; diamyl ester ofsodium sulfosuccinic acid; dihexyl ester of sodium sulfosuccinic acid;and dioctyl esters of sodium sulfosuccinic acid.

Other suitable anionic surfactants include olefin sulfonates havingabout 10 to about 24 carbon atoms. In addition to the true alkenesulfonates and a proportion of hydroxy-alkanesulfonates, the olefinsulfonates can contain minor amounts of other materials, such as alkenedisulfonates depending upon the reaction conditions, proportion ofreactants, the nature of the starting olefins and impurities in theolefin stock and side reactions during the sulfonation process. A nonlimiting example of such an alpha-olefin sulfonate mixture is describedin U.S. Pat. No. 3,332,880.

Another class of anionic surfactants suitable for use in thecompositions are the beta-alkyloxy alkane sulfonates. These surfactantsconform to the formula

where R1 is a straight chain alkyl group having from about 6 to about 20carbon atoms, R2 is a lower alkyl group having from about 1 to about 3carbon atoms, alternatively 1 carbon atom, and M is a water-solublecation as described hereinbefore.

Additional anionic surfactants suitable for use in the compositionsinclude ammonium lauryl sulfate, ammonium laureth sulfate, ammoniumlaureth-1 sulfate, ammonium laureth-2 sulfate, ammonium laureth-3sulfate, triethanolamine lauryl sulfate, triethanolamine laurethsulfate, triethanolamine laureth-1 sulfate, triethanolamine laureth-2sulfate, triethanolamine laureth-3 sulfate, monoethanolamine laurylsulfate, monoethanolamine laureth sulfate, diethanolamine laurylsulfate, diethanolamine laureth sulfate, lauric monoglyceride sodiumsulfate, sodium lauryl sulfate, sodium laureth sulfate, potassium laurylsulfate, potassium laureth sulfate, sodium lauryl sarcosinate, sodiumlauroyl sarcosinate, lauryl sarcosine, cocoyl sarcosine, ammonium cocoylsulfate, ammonium lauroyl sulfate, sodium cocoyl sulfate, sodium lauroylsulfate, potassium cocoyl sulfate, potassium lauryl sulfate,monoethanolamine cocoyl sulfate, monoethanolamine lauryl sulfate, sodiumtridecyl benzene sulfonate, sodium dodecyl benzene sulfonate, sodiumcocoyl isethionate, ammonium decyl sulfate, sodium decyl sulfate,ammonium undecyl sulfate, and ammonium undecyl sulfate and combinationsthereof.

In one embodiment of the present invention, one or more of thesurfactants is an alkyl sulfate. In one embodiment the one or more alkylsulfates has an average moles of ethoxylation of from about 0.0 to about1.9, in another embodiment the one or more alkyl sulfates has an averagemoles of ethoxylation of from about 0.0 to about 1.5, and in yet anotherembodiment the one or more alkyl sulfates has an average moles ofethoxylation of from about 0.0 to about 1.0. In one embodiment the oneor more alkyl sulfates comprises an ammonium counter ion. Suitableexamples of such surfactants with an ammonium counter ion include, butare not limited to, ammonium lauryl sulfate, ammonium laureth-1 sulfate,ammonium laureth-2 sulfate, and combinations thereof.

In one embodiment, one or more Group I surfactants are selected fromalkyl sulfates with the following structure:

wherein R¹ is selected from C-linked monovalent substituents selectedfrom the group consisting of substituted or unsubstituted, straight orbranched alkyl or unsaturated alkyl systems comprising an average of 9.0to 11.9 carbon atoms; R² is selected from the group consisting ofC-linked divalent straight or branched alkyl systems comprising 2 to 3carbon atoms; M⁺ is a monovalent counterion selected from sodium,ammonium or protonated triethanolamine; and x is 0.0 to 3.0. In oneembodiment, one or more of the alkyl sulfate surfactants according tothe above structure comprise an average moles of ethoxylation of fromabout 0.0 to about 1.9, in another embodiment the alkyl sulfatesurfactants according to the above structure comprise an average molesof ethoxylation of from about 0.0 to about 1.5, and in yet anotherembodiment the alkyl sulfate surfactants according to the abovestructure comprise an average moles of ethoxylation of from about 0.0 toabout 1.0. Suitable examples include ammonium decyl sulfate, sodiumdecyl sulfate, ammonium undeceyl sulfate, sodium undecyl sulfate,triethanolamine decyl sulfate, or triethanolamine undecyl sulfate. Inone embodiment the anionic surfactant of the present invention includesammonium undecyl sulfate.

Group II Surfactants

The Group II surfactants of the present invention include one or moreamphoteric surfactants, zwitterionic surfactants, and/or combinationsthereof. Suitable amphoteric or zwitterionic surfactants for use in thecomposition herein include those which are known for use in hair care orother personal care cleansing. Concentration of such amphotericsurfactants, zwitterionic surfactants and/or combinations thereof, rangefrom about 1.0% to about 52.5% weight % of dry solids. Non limitingexamples of suitable zwitterionic or amphoteric surfactants aredescribed in U.S. Pat. No. 5,104,646 (Bolich Jr. et al.), U.S. Pat. No.5,106,609 (Bolich Jr. et al.).

Amphoteric surfactants suitable for use in the composition are wellknown in the art, and include those surfactants broadly described asderivatives of aliphatic secondary and tertiary amines in which thealiphatic radical can be straight or branched chain and wherein one ofthe aliphatic substituents contains from about 8 to about 18 carbonatoms and one contains an anionic group such as carboxy, sulfonate,sulfate, phosphate, or phosphonate. Suitable examples of such amphotericsurfactants include, but are not limited to, sodium cocaminopropionate,sodium cocaminodipropionate, sodium cocoamphoacetate, sodiumcocoamphohydroxypropylsulfonate, sodium cocoamphopropionate, sodiumcornamphopropionate, sodium lauraminopropionate, sodiumlauroamphoacetate, sodium lauroamphohydroxypropylsulfonate, sodiumlauroamphopropionate, sodium cornamphopropionate, sodiumlauriminodipropionate, ammonium cocaminopropionate, ammoniumcocaminodipropionate, ammonium cocoamphoacetate, ammoniumcocoamphohydroxypropylsulfonate, ammonium cocoamphopropionate, ammoniumcornamphopropionate, ammonium lauraminopropionate, ammoniumlauroamphoacetate, ammonium lauroamphohydroxypropylsulfonate, ammoniumlauroamphopropionate, ammonium cornamphopropionate, ammoniumlauriminodipropionate, triethanonlamine cocaminopropionate,triethanonlamine cocaminodipropionate, triethanonlaminecocoamphoacetate, triethanonlamine cocoamphohydroxypropylsulfonate,triethanonlamine cocoamphopropionate, triethanonlaminecornamphopropionate, triethanonlamine lauraminopropionate,triethanonlamine lauroamphoacetate, triethanonlaminelauroamphohydroxypropylsulfonate, triethanonlamine lauroamphopropionate,triethanonlamine cornamphopropionate, triethanonlaminelauriminodipropionate, cocoamphodipropionic acid, disodiumcaproamphodiacetate, disodium caproamphoadipropionate, disodiumcapryloamphodiacetate, disodium capryloamphodipriopionate, disodiumcocoamphocarboxyethylhydroxypropylsulfonate, dis odiumcocoamphodiacetate, dis odium cocoamphodipropionate, disodiumdicarboxyethylcocopropylenediamine, disodium laureth-5carboxyamphodiacetate, disodium lauriminodipropionate, disodiumlauroamphodiacetate, disodium lauroamphodipropionate, disodiumoleoamphodipropionate, disodium PPG-2-isodecethy-7carboxyamphodiacetate, lauraminopropionic acid, lauroamphodipropionicacid, lauryl aminopropylglycine, lauryl diethylenediaminoglycine, andcombinations thereof.

In one embodiment, the amphoteric surfactant is a surfactant accordingto the following structure:

wherein R1 is a C-linked monovalent substituent selected from the groupconsisting of substituted alkyl systems comprising 9 to 15 carbon atoms,unsubstituted alkyl systems comprising 9 to 15 carbon atoms, straightalkyl systems comprising 9 to 15 carbon atoms, branched alkyl systemscomprising 9 to 15 carbon atoms, and unsaturated alkyl systemscomprising 9 to 15 carbon atoms; R2, R3, and R4 are each independentlyselected from the group consisting of C-linked divalent straight alkylsystems comprising 1 to 3 carbon atoms, and C-linked divalent branchedalkyl systems comprising 1 to 3 carbon atoms; and M+ is a monovalentcounterion selected from the group consisting of sodium, ammonium andprotonated triethanolamine Specific examples of suitable surfactantsinclude sodium cocoamphoacetate, sodium cocoamphodiacetate, sodiumlauroamphoacetate, sodium lauroamphodiacetate, ammoniumlauroamphoacetate, ammonium cocoamphoacetate, triethanolaminelauroamphoacetate, and triethanolamine cocoamphoacetate.

Zwitterionic surfactants suitable for use in the composition are wellknown in the art, and include those surfactants broadly described asderivatives of aliphatic quaternary ammonium, phosphonium, and sulfoniumcompounds, in which the aliphatic radicals can be straight or branchedchain, and wherein one of the aliphatic substituents contains from about8 to about 18 carbon atoms and one contains an anionic group such ascarboxy, sulfonate, sulfate, phosphate or phosphonate. Suitablezwitterionic surfactants include, but are not limited to, cocamidoethylbetaine, cocamidopropylamine oxide, cocamidopropyl betaine,cocamidopropyl dimethylaminohydroxypropyl hydrolyzed collagen,cocamidopropyldimonium hydroxypropyl hydrolyzed collagen, cocamidopropylhydroxysultaine, cocobetaineamido amphopropionate, coco-betaine,coco-hydroxysultaine, coco/oleamidopropyl betaine, coco-sultaine,lauramidopropyl betaine, lauryl betaine, lauryl hydroxysultaine, laurylsultaine, and combinations thereof.

Optional Surfactants

The compositions of the present invention may further compriseadditional surfactants for use in combination with the anionic detersivesurfactant component described hereinbefore. Suitable optionalsurfactants include nonionic and cationic surfactants. Any suchsurfactant known in the art for use in hair or personal care productsmay be used, provided that the optional additional surfactant is alsochemically and physically compatible with the essential components ofthe composition, or does not otherwise unduly impair productperformance, aesthetics or stability. The concentration of the optionaladditional surfactants in the composition may vary with the cleansing orlather performance desired, the optional surfactant selected, thedesired product concentration, the presence of other components in thecomposition, and other factors well known in the art.

Non limiting examples of other anionic, zwitterionic, amphoteric oroptional additional surfactants suitable for use in the compositions aredescribed in McCutcheon's, Emulsifiers and Detergents, 1989 Annual,published by M. C. Publishing Co., and U.S. Pat. Nos. 3,929,678,2,658,072; 2,438,091; 2,528,378.

Plasticizer

The dissolvable solid articles of the present invention may furthercomprise a water soluble plasticizing agent suitable for use in personalcare compositions. The water soluble plasticizer can be included in thearticle at a level of from about 0.1% to about 25% by weight of thearticle. Non-limiting examples of suitable plasticizing agents includepolyols, copolyols, and polyesters. Examples of useful polyols include,but are not limited to, glycerin, diglycerin, propylene glycol, ethyleneglycol, butylene glycol, pentylene glycol, polyethylene glycol(200-600), polyhydric low molecular weight alcohols (e.g., C2-C8alcohols); mono di- and oligo-saccharides such as fructose, glucose,sucrose, maltose, lactose, and high fructose corn syrup solids.

Optional Ingredients

The dissolvable solid article may further comprise other optionalingredients that are known for use or otherwise useful in compositions,provided that such optional materials are compatible with the selectedessential materials described herein, or do not otherwise unduly impairproduct performance.

Such optional ingredients are most typically those materials approvedfor use in cosmetics and that are described in reference books such asthe CTFA Cosmetic Ingredient Handbook, Second Edition, The Cosmetic,Toiletries, and Fragrance Association, Inc. 1988, 1992.

Emulsifiers suitable as an optional ingredient herein include mono- anddi-glycerides, fatty alcohols, polyglycerol esters, propylene glycolesters, sorbitan esters and other emulsifiers known or otherwisecommonly used to stabilized air interfaces, as for example those usedduring preparation of aerated foodstuffs such as cakes and other bakedgoods and confectionary products, or the stabilization of cosmetics suchas hair mousses.

Further non-limiting examples of such optional ingredients includepreservatives, perfumes or fragrances, coloring agents or dyes,conditioning agents, hair bleaching agents, thickeners, moisturizers,emollients, pharmaceutical actives, vitamins or nutrients, sunscreens,deodorants, sensates, plant extracts, nutrients, astringents, cosmeticparticles, absorbent particles, adhesive particles, hair fixatives,fibers, reactive agents, skin lightening agents, skin tanning agents,anti-dandruff agents, perfumes, exfoliating agents, acids, bases,humectants, enzymes, suspending agents, pH modifiers, hair colorants,hair perming agents, pigment particles, anti-acne agents, anti-microbialagents, sunscreens, tanning agents, exfoliation particles, hair growthor restorer agents, insect repellents, shaving lotion agents,co-solvents or other additional solvents, and similar other materials.

Additional anti-bacterial actives can be added at a level of 0.15% toabout 1.5%. Such anti-bacterial actives are, for example: CLIMBAZOLE;Piroctone Olamine; CHLORHEXIDINE; CHLORHEXIDINE DIHYDROCHLORIDE;HEXAMIDINE DIISETHIONATE; CHLORPHENESIN; POTASSIUM SALICYLATE; ZINCPYRITHIONE; PHENOXYETHANOL; and combinations thereof.

Dissolvable Solid Articles

The dissolvable solid article has a pH of from about 3 to about 5.1,alternatively from about 3.5 to about 4.9, alternatively from about 3.8to about 4.8, when dissolved with 30 parts water to 1 part of thedissolvable solid article (weight basis).

The term “solid” as used herein refers to the ability of an article tosubstantially retain its shape (i.e., without any visible change in itsshape) at 20° C. and under the atmospheric pressure, when no externalforce is applied thereto.

The term “flexible” as used herein refers to the ability of an articleto withstand stress without breakage or significant fracture when it isbent at 90° along a center line perpendicular to its longitudinaldirection. Alternatively, such article can undergo significant elasticdeformation and is characterized by a Young's Modulus of no more than 5GPa, alternatively no more than 1 GPa, alternatively no more than 0.5GPa, alternatively no more than 0.2 GPa.

The dissolvable solid article useful herein is capable of dissolving inthe liquid, especially aqueous carrier, more specifically water. Watercan be added to 1 part of the article, from about 1 100 parts,alternatively from about 5 to about 50 parts, alternatively from about10 to about 40 parts.

As used herein, “dissolvable” means that the dissolvable solid articleis completely soluble in water or it provides a uniform dispersion uponmixing in water according to the hand dissolution test. The dissolvablesolid article has a hand dissolution value of from about 0 to about 30strokes, alternatively from about 0 to about 25 strokes, alternativelyfrom about 0 to about 20 strokes, and alternatively from about Oto about15 strokes, as measured by the Hand Dissolution Method. “0 stroke” mean,just by adding water, the article is dissolved without any shear or handstroke.

The dissolvable solid article is alternatively porous, and can becharacterized by a density ranging from 0.050 g/cm³ to about 0.380g/cm³, alternatively from 0.06 grams/cm³ to 0.3 grams/cm³, alternativelyfrom 0.07 grams/cm³ to 0.2 grams/cm³, alternatively from 0.08 grams/cm³to 0.15 grams/cm³. The dissolvable solid structure of the presentinvention can be provided in the form of a dissolvable solid articlecomprising one or more flexible, dissolvable, porous sheets, whereineach of said two or more sheets is characterized by being an open-celledfoam, a fibrous structure, and the like. The porous sheets can beoptionally bonded together via a bonding means (e.g., heat, moisture,ultrasonic, pressure, and the like).

The term “open celled foam” or “open cell pore structure” as used hereinrefers to a solid, interconnected, polymer-containing matrix thatdefines a network of spaces or cells that contain a gas, typically a gas(such as air), while maintaining the physical strength and cohesivenessof the solid. The interconnectivity of the structure may be described bya Percent Open Cell Content, which is measured by Test 1 disclosedhereinafter. The dissolvable solid article useful herein can becharacterized by a Percent Open Cell Content of from 80% to 100%.

Hand Dissolution Test Method Materials Needed:

Dissolvable solid structures to be tested: 3-5 dissolvable solidstructure s (finished product samples) are tested so that an average ofthe number of strokes for each if the individual dissolvable solidstructure samples is calculated and recorded as the Average HandDissolution value for the dissolvable solid structure. For this method,the entire consumer saleable or consumer use dissolvable solid structureis tested. If the entire consumer saleable or consumer use dissolvablesolid structure has a footprint greater than 5 cm², then first cut thedissolvable solid structure to have a footprint of 5 cm².

Nitrile Gloves

5 ml syringe

Plastic Weigh boat (˜3M×3 in)

50 mL Glass beaker

Water (City of Singapore Water or equivalent having the followingproperties: Total Hardness=64 mg/L as CaCO2; Calcium content=23 mg/L;Magnesium content=1.58 mg/L; Phosphate content=0.017 mg/L)

Water used is 3 gpg hardness and 23° C.+/−2° C.

Protocol:

-   -   Add 10 mL of water to glass beaker.    -   Cool water in beaker until water is at a temperature of 23°        C.+/−2° C.    -   Transfer 4 mL of the water from the beaker into the weigh boat        via the syringe.    -   Within 10 seconds of transferring the water to the weigh boat,        place dissolvable solid structure sample in palm of gloved hand        (hand in cupped position in non-dominant hand to hold        dissolvable solid structure sample).    -   Using dominant hand, add water quickly from the weigh boat to        the dissolvable solid structure sample and allow to immediately        wet for a period of 5-10 seconds.    -   Rub with opposite dominant hand (also gloved) in 2 rapid        circular strokes.    -   Visually examine the dissolvable solid structure sample in hand        after the 2 strokes. If dissolvable solid structure sample is        completely dissolved, record number of strokes=2 Dissolution        Strokes. If not completely dissolved, rub remaining dissolvable        solid structure sample for 2 more circular strokes (4 total) and        observe degree of dissolution. If the dissolvable solid        structure sample contains no solid pieces after the 2 additional        strokes, record number of strokes=4 Dissolution Strokes. If        after the 4 strokes total, the dissolvable solid structure        sample still contains solid pieces of un-dissolved dissolvable        solid structure sample, continue rubbing remaining dissolvable        solid structure sample in additional 2 circular strokes and        check if there are any remaining solid pieces of dissolvable        solid structure sample after each additional 2 strokes until        dissolvable solid structure sample is completely dissolved or        until reaching a total of 30 strokes, whichever comes first.        Record the total number of strokes. Record 30 Dissolution        Strokes even if solid dissolvable solid structure sample pieces        remain after the maximum of 30 strokes.    -   Repeat this process for each of the additional 4 dissolvable        solid structure samples.    -   Calculate the arithmetic mean of the recorded values of        Dissolution Strokes for the 5 individual dissolvable solid        structure samples and record as the Average Hand Dissolution

Value for the dissolvable solid structure. The Average Hand DissolutionValue is reported to the nearest single Dissolution Stroke unit.

Test 1: Percent Open Cell Content of the Sheet Article

The Percent Open Cell Content is measured via gas pycnometry. Gaspycnometry is a common analytical technique that uses a gas displacementmethod to measure volume accurately. Inert gases, such as helium ornitrogen, are used as the displacement medium. A sample of the solidsheet article of the present invention is sealed in the instrumentcompartment of known volume, the appropriate inert gas is admitted, andthen expanded into another precision internal volume. The pressurebefore and after expansion is measured and used to compute the samplearticle volume.

ASTM Standard Test Method D2856 provides a procedure for determining thepercentage of open cells using an older model of an air comparisonpycnometer. This device is no longer manufactured. However, one candetermine the percentage of open cells conveniently and with precisionby performing a test which uses Micromeritics' AccuPyc Pycnometer. TheASTM procedure D2856 describes 5 methods (A, B, C, D, and E) fordetermining the percent of open cells of foam materials. For theseexperiments, the samples can be analyzed using an Accupyc 1340 usingnitrogen gas with the ASTM foampyc software. Method C of the ASTMprocedure is to be used to calculate to percent open cells. This methodsimply compares the geometric volume as determined using calipers andstandard volume calculations to the open cell volume as measured by theAccupyc, according to the following equation:

Open cell percentage=Open cell volume of sample/Geometric volume ofsample*100

It is recommended that these measurements be conducted by MicromereticsAnalytical Services, Inc. (One Micromeritics Dr, Suite 200, Norcross,Ga. 30093). More information on this technique is available on theMicromeretics Analytical Services web sites (www.particletesting.com orwww.micromeritics.com), or published in “Analytical Methods in Fineparticle Technology” by Clyde Orr and Paul Webb.

The dissolvable solid articles can be characterized by Overall AveragePore Size of from 100 μm to 2000 μm, as measured by the Micro-CT methoddescribed in Test 2 hereinafter. The Overall Average Pore Size definesthe porosity of the dissolvable solid article.

The dissolvable solid articles can be characterized by an Average CellWall Thickness or Average Filament Diameter of from 1 μm to 200 μm,alternatively from 10 μm to 100 μm, alternatively from 20 μm to 80 μm;still alternatively from about 25 μm to 60 μm, as measured by Test 2hereinafter.

Test 2: Micro-Computed Tomographic (μCT) Method for Determining Overallor Regional Average Pore Size and Average Cell Wall Thickness of theOpen Cell Foams (OCF)

Porosity is the ratio between void-space to the total space occupied bythe OCF. Porosity can be calculated from μCT scans by segmenting thevoid space via thresholding and determining the ratio of void voxels tototal voxels. Similarly, solid volume fraction (SVF) is the ratiobetween solid-space to the total space, and SVF can be calculated as theratio of occupied voxels to total voxels. Both Porosity and SVF areaverage scalar-values that do not provide structural information, suchas, pore size distribution in the height-direction of the OCF, or theaverage cell wall thickness of OCF struts.

To characterize the 3D structure of the OCFs, samples are imaged using aμCT X-ray scanning instrument capable of acquiring a dataset at highisotropic spatial resolution. One example of suitable instrumentation isthe SCANCO system model 50 μCT scanner (Scanco Medical AG, Brüttisellen,Switzerland) operated with the following settings: energy level of 45kVp at 133 μA; 3000 projections; 15 mm field of view; 750 ms integrationtime; an averaging of 5; and a voxel size of 3 μm per pixel. Afterscanning and subsequent data reconstruction is complete, the scannersystem creates a 16 bit data set, referred to as an ISQ file, where greylevels reflect changes in x-ray attenuation, which in turn relates tomaterial density. The ISQ file is then converted to 8 bit using ascaling factor.

Scanned OCF samples are normally prepared by punching a core ofapproximately 14 mm in diameter. The OCF punch is laid flat on alow-attenuating foam and then mounted in a 15 mm diameter plasticcylindrical tube for scanning Scans of the samples are acquired suchthat the entire volume of all the mounted cut sample is included in thedataset. From this larger dataset, a smaller sub-volume of the sampledataset is extracted from the total cross section of the scanned OCF,creating a 3D slab of data, where pores can be qualitatively assessedwithout edge/boundary effects.

To characterize pore-size distribution in the height-direction, and thestrut-size, Local Thickness Map algorithm, or LTM, is implemented on thesubvolume dataset. The LTM Method starts with a Euclidean DistanceMapping (EDM) which assigns grey level values equal to the distance eachvoid voxel is from its nearest boundary. Based on the EDM data, the 3Dvoid space representing pores (or the 3D solid space representingstruts) is tessellated with spheres sized to match the EDM values.Voxels enclosed by the spheres are assigned the radius value of thelargest sphere. In other words, each void voxel (or solid voxel forstruts) is assigned the radial value of the largest sphere that thatboth fits within the void space boundary (or solid space boundary forstruts) and includes the assigned voxel.

The 3D labelled sphere distribution output from the LTM data scan can betreated as a stack of two dimensional images in the height-direction (orZ-direction) and used to estimate the change in sphere diameter fromslice to slice as a function of OCF depth. The strut thickness istreated as a 3D dataset and an average value can be assessed for thewhole or parts of the subvolume. The calculations and measurements weredone using AVIZO Lite (9.2.0) from Thermo Fisher Scientific and MATLAB(R2017a) from Mathworks.

The dissolvable solid articles can be characterized by a SpecificSurface Area of from 0.03 m²/g to 0.25 m²/g, alternatively from 0.04m²/g to 0.22 m²/g, alternatively from 0.05 m²/g to 0.2 m²/g,alternatively from 0.1 m²/g to 0.18 m²/g. as measured by Test 3described hereinafter. The Specific Surface Area of the solid sheet ofthe present invention may be indicative of its porosity and may impactits dissolution rate, e.g., the greater the Specific Surface Area, themore porous the sheet and the faster its dissolution rate.

Test 3: Specific Surface Area of the Sheet Article

The Specific Surface Area of the flexible, porous, dissolvable solidsheet article is measured via a gas adsorption technique. Surface Areais a measure of the exposed surface of a solid sample on the molecularscale. The BET (Brunauer, Emmet, and Teller) theory is the most popularmodel used to determine the surface area and is based upon gasadsorption isotherms. Gas Adsorption uses physical adsorption andcapillary condensation to measure a gas adsorption isotherm. Thetechnique is summarized by the following steps; a sample is placed in asample tube and is heated under vacuum or flowing gas to removecontamination on the surface of the sample. The sample weight isobtained by subtracting the empty sample tube weight from the combinedweight of the degassed sample and the sample tube. The sample tube isthen placed on the analysis port and the analysis is started. The firststep in the analysis process is to evacuate the sample tube, followed bya measurement of the free space volume in the sample tube using heliumgas at liquid nitrogen temperatures. The sample is then evacuated asecond time to remove the helium gas. The instrument then beginscollecting the adsorption isotherm by dosing krypton gas at userspecified intervals until the requested pressure measurements areachieved. Samples may then analyzed using an ASAP 2420 with krypton gasadsorption. It is recommended that these measurements be conducted byMicromeretics Analytical Services, Inc. (One Micromeritics Dr, Suite200, Norcross, Ga. 30093). More information on this technique isavailable on the Micromeretics Analytical Services web sites(www.particletesting.com or www.micromeritics.com), or published in abook, “Analytical Methods in Fine particle Technology”, by Clyde Orr andPaul Webb.

The dissolvable solid articles can be characterized by a final moisturecontent of from 0.5% to 25%, alternatively from 1% to 20%, alternativelyfrom 3% to 10%, by weight of said article as measured by Test 4hereinafter. An appropriate final moisture content in the resultingsolid sheet may ensure the desired flexibility/deformability of thesheet, as well as providing soft/smooth sensory feel to the consumers.If the final moisture content is too low, the sheet may be too brittleor rigid. If the final moisture content is too high, the sheet may betoo sticky, and its overall structural integrity may be compromised.

Test 4: Final Moisture Content of the Sheet Article

Final moisture content of the solid sheet article of the presentinvention is obtained by using a Mettler Toledo HX204 Moisture Analyzer(S/N B706673091). A minimum of 1 g of the dried sheet article is placedon the measuring tray. The standard program is then executed, withadditional program settings of 10 minutes analysis time and atemperature of 110° C.

Product

The dissolvable solid articles can be any product including, forexample, personal care products, home care products, surface cleaningproducts, general cleaning products. Alternatively, the product is apersonal care product. Such personal products include, for example,personal cleansing products such as body, facial and/or hand cleansingproducts, skin care products such as Lotion, facial mist, gel, cream,hair care products such as shampoos and conditioners.

Method of Use

The method of use of the dissolvable solid article may comprise thesteps of: a) applying an effective amount of the dissolvable poroussolid to the hand, b) wetting the dissolvable porous solid with waterand rubbing to dissolve the solid, c) applying the dissolved material tothe subject such as hair and/or skin, and d) rinsing the dissolvedmaterial from the subject using water.

Examples

The following examples further describe and demonstrate embodimentswithin the scope of the present invention. The examples are given solelyfor the purpose of illustration and are not to be construed aslimitations of the present invention, as many variations thereof arepossible without departing from the spirit and scope of the invention.Where applicable, ingredients are identified by chemical or CTFA name,or otherwise defined below.

Dissolvable Solid Article Composition

Ingredient Name CEx. i CEx. ii Ex. 1 Water 5.84 5.49 5.61 Glycerin 6.586.19 6.33 Sodium lauramidopropyl betaine 7.23 6.80 6.95 Sodium MethylCocoyl Taurate 19.23 18.08 18.50 Polyvinyl Alcohol (BP-17 having 21.4120.13 20.59 86-90% degree of hydrolysis, Approximate MW(weight average)= 70,000-120,000 daltons, available from Liwei Chemical Co. Ltd., China)Sodium Cocoyl Isethionate 10.84 10.19 10.43 Sodium Cocoyl Glutamate10.84 10.19 10.43 EDTA 1.00 1.00 Sodium Benzoate 0.50 0.50 PotassiumSorbate 0.50 0.50 Symsave H (Hydroxyacetophenone) 2.00 2.00 Symdiol 68(50:50 blend of 1,2- 1.00 1.00 Hexanediol and 1,2-Octanediol) salicylicacid 0.50 Sodium citrate 7.51 7.51 5.00 Citric acid 10.80 10.80 11.00100 100 100 C4 Result (gram negative) −16.15 −11.54 69.28 pH 4.75 4.774.26

Dissolvable Solid Article Composition

Ingredient Name Ex. 2 Ex. 3 CEx. iii Ex. 4 Ex. 5 Ex. 6 Ex. 7 Water 10.0010.00 10.00 10.00 10.00 10.00 10.00 Glycerin 7.55 7.65 8.22 8.30 8.218.22 8.12 Sodium lauroamphoacetate 9.06 9.18 9.87 9.97 9.86 9.87 9.75Sodium Laureth ethoxy (1) 38.85 39.34 42.30 42.72 42.25 42.31 41.79sulfate (SLE1S) Polyvinyl Alcohol BP-17 19.81 20.06 21.57 21.78 21.5521.58 21.32 having 86-90% degree of hydrolysis, Approximate MW(weightaverage) = 70,000-120,000 daltons, available from Liwei Chemical Co.Ltd., China Denatonium Benzoate 0.012 0.012 0.013 0.013 0.013 0.0130.013 Perfume 1.17 1.18 1.27 1.28 1.27 1.27 1.25 Sodium Benzoate 0.480.48 0.45 0.45 0.44 0.44 0.44 EDTA 2Na 0.97 0.97 0.90 0.89 0.89 0.890.88 Salicylic acid 0.48 0.45 0.45 0.44 0.44 0.44 Symdiol 68 (50:50blend of 0.97 0.48 0.90 0.89 0.89 0.89 0.88 1,2-Hexanediol and 1,2-Octanediol) Potassium Sorbate 0.45 Symsave H 0.90 (Hydroxyacetophenone)Sodium Citrate 2.90 2.90 Citric Acid 7.74 7.74 2.70 2.66 2.67 2.63Lactic acid 2.68 6N HCl 0.57 Sorbic Acid 1.52 Benzoic Acid 2.48 PhyticAcid 1.41 C4 Result (gram negative) 99.99 97.96 −4.59 99.59 73.68 84.3698.36 pH 4.25 4.25 5.52 4.48 5.02 4.72 4.68

C4 Result (Gram Negative) Preparation of Bacterial Suspension

A 1×10⁶˜9×10⁶ CFU/mL S. aureus ATCC6538 or E. coli ATCC25922 bacterialsuspension was prepared by washing off the bacteria from agar plate with0.03M Phosphate Buffered Solution (PBS).

Preparation of Control Sample

5 mL Saline solution (0.85% w/v NaCl) was used as a Control sample forthe test.

Preparation of Test Samples

Dissolve and dilute 1 part of the composition in the above table with 30parts of water to prepare Test sample.

Test

100 μl of the bacterial suspension was added to 5 mL of the sample toachieve 1×10⁴˜9×10⁴ CFU/mL to make a mixture, and the mixture wasvortexed and stand for 2 min. Then, 1.0 mL of the mixture wastransferred into a test tube containing 9.0 mL of 0.03M PBS and mixed todiluted. Serial dilutions were performed to dilute the concentration ofthe mixture to 10000 times with 0.03M PBS. The serially diluted mixturewas plated by adding 1.0 mL of such serially diluted mixture into 2petri dishes.

Molten (˜20 mL, 40˜45° C.) Tryptic Soy Agar (TSA) was poured into thepetri dish and swirled to mix. The agar was allowed to cool and hardenbefore turning over and incubated at 35±2° C. for 48 h.

Bactericidal rate is calculated following below:

where:

$X_{4} = {\frac{( {A - B} )}{A} \times 100\%}$

X₄=bactericidal rate, %A=mean bacteria count on control sampleB=mean bacteria count on tested sample

Criteria for Evaluation

If the bactericidal rate is ≥50˜90%, it can be reported that the testedproducts have bacteriostatic effect.

If the bactericidal rate is ≥90%, it can be reported that the testedproducts have strong bacteriostatic effect.

The compositions of Ex. 1 to Ex. 7 are examples of the presentinvention. The compositions of CEx. i to CEx.iii are comparativeexamples. The composition CEx.i does not contain anti-bacterial active,the composition CEx. ii contains higher % of citric acid and its salt,and the composition of CEx. iii has a higher pH.

The compositions of Ex. 1 to Ex. 7 as examples of the present inventionprovide anti-bacterial benefit even after dissolution of the article,while controlling the concentration of anti-bacterial active ingredientin the solid articles. The compositions of CEx. i to CEx.iii ascomparative examples do not provide anti-bacterial benefit.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A dissolvable solid article, comprising by weightof the article: a. from about 10% to about 50% of a water solublepolymer; b. from about 20% to about 80% of a surfactant; c. from about0.5% to about 2% of diaminocarboxylic acid chelants and salts thereofhaving an average molecular weight in acid form of from about 250 toabout 450 daltons and having a weighted log P value at pH 4 of fromabout −12 to about −7; d. from about 0.1% to about 6% of an aromaticcarboxylic acid and salts thereof having an average molecular weight inacid form of from about 100 to about 400 daltons and having a weightedlog P value at pH 4 of from about −2 to about 4; e. from about 0.1% toabout 18% of a non-aromatic organic alpha hydroxy acid and saltsthereof; wherein the dissolvable solid article has a pH of from about 3to about 5.1 when dissolved with 30 parts water to 1 part of thedissolvable solid article.
 2. The dissolvable solid article of claim 1,wherein the dissolvable solid article has a pH of from about 3.5 toabout 4.9 when dissolved with 30 parts water to 1 part of thedissolvable solid article.
 3. The dissolvable solid article of any ofthe preceding claims, wherein the dissolvable solid article has a pH offrom about 3.8 to about 4.8 when dissolved with 30 parts water to 1 partof the dissolvable solid article.
 4. The dissolvable solid article ofany of the preceding claims further comprising from about 0.1% to about2.0% of a diol having an average molecular weight of from about 90 toabout 500 daltons and a weighted log P value at pH 4 of from about −1 toabout
 12. 5. The dissolvable solid article of any of the precedingclaims, wherein the dissolvable solid article comprises two or moreflexible, dissolvable, porous sheets.
 6. The dissolvable solid articleof any of the preceding claims, wherein the dissolvable solid articlehas a density ranging from about 0.050 g/cm³ to about 0.380 g/cm³.